asgjkfhklgankjhgads UNCORRECTEDRip Current | News in Oceanography PROOF Superstorm Sandy A Series of Unfortunate Events?
By Charles H. Greene, Jennifer A. Francis, and Bruce C. Monger
As we reflect upon the rash of extreme what made Sandy become so unusual the eastern seaboard. weather observed during 2012, no were the atmospheric interactions that Second, while on this apparently single event had as large an impact on transformed it into a monster hybrid unprecedented westward trajectory, the economy and political landscape storm that combined the worst features Sandy converged with an extra-tropical of the United States as Superstorm of a late-season hurricane and an extra- cyclone, a developing early “winter” Sandy (e.g., Bloomberg Businessweek: tropical cyclone. Unlike a typical hur- nor’easter, which transformed it from http://www.businessweek.com/ ricane, this huge and powerful hybrid a weakening late-October hurricane/ articles/2012-11-01/its-global-warming- storm did not lose strength after making tropical storm into an extra-tropical stupid). Images of flooded subway landfall because it was supercharged hybrid superstorm. At the center of stations in New York City, demol- with energy derived from a southward this superstorm, atmospheric pres- ished towns on the New Jersey shore, dip in the jet stream over the Mississippi sures were the lowest ever recorded for and autumn blizzard conditions in Valley that ushered in an invasion of cold a storm making landfall north of Cape Appalachia will be forever etched in the Arctic air (Figure 1). Thus, a useful way Hatteras, NC. In addition, Superstorm nation’s psyche for quite some time. With to look at the anthropogenic climate- Sandy exhibited the second-largest the increasing frequency of extreme change connection is to ask why were the extent (> 1.4 million km2) of storm- weather events serving as a backdrop, extra-tropical conditions so unusual? force winds for any extra-tropical storm many people are asking what role, if any, Let’s review the facts: derived from a hurricane (second only to did anthropogenic climate change play in First, a strong high-pressure block- Hurricane Olga in 2001). the development of Superstorm Sandy? ing pattern over Greenland and the Third, the combination of Superstorm We believe that the recent record-break- northwest Atlantic prevented Sandy Sandy’s extremely low atmospheric ing losses of Arctic sea ice may figure from steering northeast and out to sea pressure and the unusually strong prominently in answering this question like most October hurricanes/tropical and in improving our understanding of storms heading up from the Caribbean. Charles H. Greene ([email protected]) is Sandy’s unusual nature. In fact, Sandy did not just track north- Director, Ocean Resources and Ecosystems While Sandy started out as a rela- ward toward New England like the Program, Cornell University, Ithaca, NY, tively normal late-season hurricane, its handful of other October tropical storms USA. Jennifer A. Francis is Research character became anything but normal that did not head out to sea (think of Professor, Institute of Marine and as the storm tracked northward along the 1991 Perfect Storm). Rather, Sandy Coastal Sciences, Rutgers University, the eastern seaboard. Unusually warm did something never observed before New Brunswick, NJ, USA. Bruce C. Monger ocean temperatures helped Sandy in records going back to 1851—it took is Senior Research Associate, Earth and maintain tropical storm characteristics a sharp turn to the west and headed Atmospheric Sciences, Cornell University, as it headed to the north. However, toward the most populated area along Ithaca, NY, USA.
8 Oceanography | Vol. 26, No. 1 UNCORRECTED PROOF a b
C o l d A Storm Surge r t Flooding Strong i H c Blizzard East Winds J A e ir Conditions Cold Blocking t Arctic Air Pattern S t re J a e t m
S t re a m
Sandy Figure 1. (a) Atmospheric conditions during Hurricane Sandy’s transit along the eastern seaboard of the United States, including the invasion of cold Arctic air into the middle latitudes of North America and the high-pressure blocking pattern in the northwest Atlantic. (b) After the convergence of tropical and extra-tropical storm systems, the hybrid Superstorm Sandy made landfall in New Jersey and New York, bringing strong winds, storm surge, and flooding to areas near the coast and blizzard conditions to Appalachia.
high-pressure block to the north created of (1) larger amplitude meanders in the of nature. And, the subsequent invasion a huge area of violent east winds that jet stream, (2) more frequent invasions of Arctic air that unleashed a fully devel- pushed water up against the eastern sea- of Arctic air masses into the middle oped nor’easter on the victims of Sandy board from Nova Scotia to New Jersey, latitudes, and (3) more frequent block- only a few days later just makes the argu- greatly exacerbating the storm surge. ing events of the kind that steered Sandy ment even less convincing that this series To literally top it off, the storm surge to the west (Francis and Vavrus, 2012; of unfortunate events was largely an combined with full-moon high tides and Greene, 2012; Greene and Monger, 2012; act of nature. huge ocean waves to produce record- Liu et al., 2012). Although a direct causal high water levels that exceeded the link has not been established between REFERENCES worst-case predictions for certain parts the atmospheric phenomena observed Francis, J.A., and S.J. Vavrus. 2012. Evidence link- ing Arctic amplification to extreme weather of New York City. in late October 2012 and the record- in mid-latitudes. Geophysical Research Now, some might argue that this was breaking sea-ice loss observed during Letters 39, L06801, http://dx.doi.org/10.1029/ 2012GL051000. just a series of unfortunate events result- the preceding summer months, all of the Greene, C.H. 2012. The winters of our discon- ing from the coincidence of many rare observations are consistent with such an tent. Scientific American 307:50–55, http:// dx.doi.org/10.1038/scientificamerican1212-50. and/or unprecedented acts of nature. For interpretation. Therefore, if one accepts Greene, C.H., and B.C. Monger. 2012. those convinced that it is very difficult this evidence and line of reasoning, and An Arctic wild card in the weather. or impossible to attribute the occurrence also takes into account the record loss Oceanography 25(2):7–9, http://dx.doi.org/ 10.5670/oceanog.2012.58. of any single extreme weather event to of Arctic sea ice this past September, Liu, J., J.A. Curry, H. Wang, M. Song, and anthropogenic climate change, this argu- then perhaps the likelihood of green- R.M. Horton. 2012. Impact of declining Arctic sea ice on winter snowfall. Proceedings of the ment is, indeed, valid. However, there house warming playing a significant role National Academy of Sciences of the United is increasing evidence that the loss of in Sandy’s evolution as an extra-tropical States of America 109:4,074–4,079, http:// dx.doi.org/10.1073/pnas.1114910109. summertime Arctic sea ice due to green- superstorm is at least as plausible as the house warming stacks the deck in favor idea that this storm was simply a freak
Oceanography | March 2013 9 UNCORRECTEDRip Current | News in Oceanography PROOF Superstorm Sandy A Series of Unfortunate Events?
By Charles H. Greene, Jennifer A. Francis, and Bruce C. Monger
As we reflect upon the rash of extreme what made Sandy become so unusual the eastern seaboard. weather observed during 2012, no were the atmospheric interactions that Second, while on this apparently single event had as large an impact on transformed it into a monster hybrid unprecedented westward trajectory, the economy and political landscape storm that combined the worst features Sandy converged with an extra-tropical of the United States as Superstorm of a late-season hurricane and an extra- cyclone, a developing early “winter” Sandy (e.g., Bloomberg Businessweek: tropical cyclone. Unlike a typical hur- nor’easter, which transformed it from http://www.businessweek.com/ ricane, this huge and powerful hybrid a weakening late-October hurricane/ articles/2012-11-01/its-global-warming- storm did not lose strength after making tropical storm into an extra-tropical stupid). Images of flooded subway landfall because it was supercharged hybrid superstorm. At the center of stations in New York City, demol- with energy derived from a southward this superstorm, atmospheric pres- ished towns on the New Jersey shore, dip in the jet stream over the Mississippi sures were the lowest ever recorded for and autumn blizzard conditions in Valley that ushered in an invasion of cold a storm making landfall north of Cape Appalachia will be forever etched in the Arctic air (Figure 1). Thus, a useful way Hatteras, NC. In addition, Superstorm nation’s psyche for quite some time. With to look at the anthropogenic climate- Sandy exhibited the second-largest the increasing frequency of extreme change connection is to ask why were the extent (> 1.4 million km2) of storm- weather events serving as a backdrop, extra-tropical conditions so unusual? force winds for any extra-tropical storm many people are asking what role, if any, Let’s review the facts: derived from a hurricane (second only to did anthropogenic climate change play in First, a strong high-pressure block- Hurricane Olga in 2001). the development of Superstorm Sandy? ing pattern over Greenland and the Third, the combination of Superstorm We believe that the recent record-break- northwest Atlantic prevented Sandy Sandy’s extremely low atmospheric ing losses of Arctic sea ice may figure from steering northeast and out to sea pressure and the unusually strong prominently in answering this question like most October hurricanes/tropical and in improving our understanding of storms heading up from the Caribbean. Charles H. Greene ([email protected]) is Sandy’s unusual nature. In fact, Sandy did not just track north- Director, Ocean Resources and Ecosystems While Sandy started out as a rela- ward toward New England like the Program, Cornell University, Ithaca, NY, tively normal late-season hurricane, its handful of other October tropical storms USA. Jennifer A. Francis is Research character became anything but normal that did not head out to sea (think of Professor, Institute of Marine and as the storm tracked northward along the 1991 Perfect Storm). Rather, Sandy Coastal Sciences, Rutgers University, the eastern seaboard. Unusually warm did something never observed before New Brunswick, NJ, USA. Bruce C. Monger ocean temperatures helped Sandy in records going back to 1851—it took is Senior Research Associate, Earth and maintain tropical storm characteristics a sharp turn to the west and headed Atmospheric Sciences, Cornell University, as it headed to the north. However, toward the most populated area along Ithaca, NY, USA.
10 Oceanography | Vol. 26, No. 1 UNCORRECTED PROOF a b
C o l d A Storm Surge r t Flooding Strong i H c Blizzard East Winds J A e ir Conditions Cold Blocking t Arctic Air Pattern S t re J a e t m
S t re a m
Sandy Figure 1. (a) Atmospheric conditions during Hurricane Sandy’s transit along the eastern seaboard of the United States, including the invasion of cold Arctic air into the middle latitudes of North America and the high-pressure blocking pattern in the northwest Atlantic. (b) After the convergence of tropical and extra-tropical storm systems, the hybrid Superstorm Sandy made landfall in New Jersey and New York, bringing strong winds, storm surge, and flooding to areas near the coast and blizzard conditions to Appalachia.
high-pressure block to the north created of (1) larger amplitude meanders in the of nature. And, the subsequent invasion a huge area of violent east winds that jet stream, (2) more frequent invasions of Arctic air that unleashed a fully devel- pushed water up against the eastern sea- of Arctic air masses into the middle oped nor’easter on the victims of Sandy board from Nova Scotia to New Jersey, latitudes, and (3) more frequent block- only a few days later just makes the argu- greatly exacerbating the storm surge. ing events of the kind that steered Sandy ment even less convincing that this series To literally top it off, the storm surge to the west (Francis and Vavrus, 2012; of unfortunate events was largely an combined with full-moon high tides and Greene, 2012; Greene and Monger, 2012; act of nature. huge ocean waves to produce record- Liu et al., 2012). Although a direct causal high water levels that exceeded the link has not been established between REFERENCES worst-case predictions for certain parts the atmospheric phenomena observed Francis, J.A., and S.J. Vavrus. 2012. Evidence link- ing Arctic amplification to extreme weather of New York City. in late October 2012 and the record- in mid-latitudes. Geophysical Research Now, some might argue that this was breaking sea-ice loss observed during Letters 39, L06801, http://dx.doi.org/10.1029/ 2012GL051000. just a series of unfortunate events result- the preceding summer months, all of the Greene, C.H. 2012. The winters of our discon- ing from the coincidence of many rare observations are consistent with such an tent. Scientific American 307:50–55, http:// dx.doi.org/10.1038/scientificamerican1212-50. and/or unprecedented acts of nature. For interpretation. Therefore, if one accepts Greene, C.H., and B.C. Monger. 2012. those convinced that it is very difficult this evidence and line of reasoning, and An Arctic wild card in the weather. or impossible to attribute the occurrence also takes into account the record loss Oceanography 25(2):7–9, http://dx.doi.org/ 10.5670/oceanog.2012.58. of any single extreme weather event to of Arctic sea ice this past September, Liu, J., J.A. Curry, H. Wang, M. Song, and anthropogenic climate change, this argu- then perhaps the likelihood of green- R.M. Horton. 2012. Impact of declining Arctic sea ice on winter snowfall. Proceedings of the ment is, indeed, valid. However, there house warming playing a significant role National Academy of Sciences of the United is increasing evidence that the loss of in Sandy’s evolution as an extra-tropical States of America 109:4,074–4,079, http:// dx.doi.org/10.1073/pnas.1114910109. summertime Arctic sea ice due to green- superstorm is at least as plausible as the house warming stacks the deck in favor idea that this storm was simply a freak
Oceanography | March 2013 11 UNCORRECTEDRip Current | News in Oceanography PROOF Superstorm Sandy A Series of Unfortunate Events?
By Charles H. Greene, Jennifer A. Francis, and Bruce C. Monger
As we reflect upon the rash of extreme what made Sandy become so unusual the eastern seaboard. weather observed during 2012, no were the atmospheric interactions that Second, while on this apparently single event had as large an impact on transformed it into a monster hybrid unprecedented westward trajectory, the economy and political landscape storm that combined the worst features Sandy converged with an extra-tropical of the United States as Superstorm of a late-season hurricane and an extra- cyclone, a developing early “winter” Sandy (e.g., Bloomberg Businessweek: tropical cyclone. Unlike a typical hur- nor’easter, which transformed it from http://www.businessweek.com/ ricane, this huge and powerful hybrid a weakening late-October hurricane/ articles/2012-11-01/its-global-warming- storm did not lose strength after making tropical storm into an extra-tropical stupid). Images of flooded subway landfall because it was supercharged hybrid superstorm. At the center of stations in New York City, demol- with energy derived from a southward this superstorm, atmospheric pres- ished towns on the New Jersey shore, dip in the jet stream over the Mississippi sures were the lowest ever recorded for and autumn blizzard conditions in Valley that ushered in an invasion of cold a storm making landfall north of Cape Appalachia will be forever etched in the Arctic air (Figure 1). Thus, a useful way Hatteras, NC. In addition, Superstorm nation’s psyche for quite some time. With to look at the anthropogenic climate- Sandy exhibited the second-largest the increasing frequency of extreme change connection is to ask why were the extent (> 1.4 million km2) of storm- weather events serving as a backdrop, extra-tropical conditions so unusual? force winds for any extra-tropical storm many people are asking what role, if any, Let’s review the facts: derived from a hurricane (second only to did anthropogenic climate change play in First, a strong high-pressure block- Hurricane Olga in 2001). the development of Superstorm Sandy? ing pattern over Greenland and the Third, the combination of Superstorm We believe that the recent record-break- northwest Atlantic prevented Sandy Sandy’s extremely low atmospheric ing losses of Arctic sea ice may figure from steering northeast and out to sea pressure and the unusually strong prominently in answering this question like most October hurricanes/tropical and in improving our understanding of storms heading up from the Caribbean. Charles H. Greene ([email protected]) is Sandy’s unusual nature. In fact, Sandy did not just track north- Director, Ocean Resources and Ecosystems While Sandy started out as a rela- ward toward New England like the Program, Cornell University, Ithaca, NY, tively normal late-season hurricane, its handful of other October tropical storms USA. Jennifer A. Francis is Research character became anything but normal that did not head out to sea (think of Professor, Institute of Marine and as the storm tracked northward along the 1991 Perfect Storm). Rather, Sandy Coastal Sciences, Rutgers University, the eastern seaboard. Unusually warm did something never observed before New Brunswick, NJ, USA. Bruce C. Monger ocean temperatures helped Sandy in records going back to 1851—it took is Senior Research Associate, Earth and maintain tropical storm characteristics a sharp turn to the west and headed Atmospheric Sciences, Cornell University, as it headed to the north. However, toward the most populated area along Ithaca, NY, USA.
12 Oceanography | Vol. 26, No. 1 UNCORRECTED PROOF a b
C o l d A Storm Surge r t Flooding Strong i H c Blizzard East Winds J A e ir Conditions Cold Blocking t Arctic Air Pattern S t re J a e t m
S t re a m
Sandy Figure 1. (a) Atmospheric conditions during Hurricane Sandy’s transit along the eastern seaboard of the United States, including the invasion of cold Arctic air into the middle latitudes of North America and the high-pressure blocking pattern in the northwest Atlantic. (b) After the convergence of tropical and extra-tropical storm systems, the hybrid Superstorm Sandy made landfall in New Jersey and New York, bringing strong winds, storm surge, and flooding to areas near the coast and blizzard conditions to Appalachia.
high-pressure block to the north created of (1) larger amplitude meanders in the of nature. And, the subsequent invasion a huge area of violent east winds that jet stream, (2) more frequent invasions of Arctic air that unleashed a fully devel- pushed water up against the eastern sea- of Arctic air masses into the middle oped nor’easter on the victims of Sandy board from Nova Scotia to New Jersey, latitudes, and (3) more frequent block- only a few days later just makes the argu- greatly exacerbating the storm surge. ing events of the kind that steered Sandy ment even less convincing that this series To literally top it off, the storm surge to the west (Francis and Vavrus, 2012; of unfortunate events was largely an combined with full-moon high tides and Greene, 2012; Greene and Monger, 2012; act of nature. huge ocean waves to produce record- Liu et al., 2012). Although a direct causal high water levels that exceeded the link has not been established between REFERENCES worst-case predictions for certain parts the atmospheric phenomena observed Francis, J.A., and S.J. Vavrus. 2012. Evidence link- ing Arctic amplification to extreme weather of New York City. in late October 2012 and the record- in mid-latitudes. Geophysical Research Now, some might argue that this was breaking sea-ice loss observed during Letters 39, L06801, http://dx.doi.org/10.1029/ 2012GL051000. just a series of unfortunate events result- the preceding summer months, all of the Greene, C.H. 2012. The winters of our discon- ing from the coincidence of many rare observations are consistent with such an tent. Scientific American 307:50–55, http:// dx.doi.org/10.1038/scientificamerican1212-50. and/or unprecedented acts of nature. For interpretation. Therefore, if one accepts Greene, C.H., and B.C. Monger. 2012. those convinced that it is very difficult this evidence and line of reasoning, and An Arctic wild card in the weather. or impossible to attribute the occurrence also takes into account the record loss Oceanography 25(2):7–9, http://dx.doi.org/ 10.5670/oceanog.2012.58. of any single extreme weather event to of Arctic sea ice this past September, Liu, J., J.A. Curry, H. Wang, M. Song, and anthropogenic climate change, this argu- then perhaps the likelihood of green- R.M. Horton. 2012. Impact of declining Arctic sea ice on winter snowfall. Proceedings of the ment is, indeed, valid. However, there house warming playing a significant role National Academy of Sciences of the United is increasing evidence that the loss of in Sandy’s evolution as an extra-tropical States of America 109:4,074–4,079, http:// dx.doi.org/10.1073/pnas.1114910109. summertime Arctic sea ice due to green- superstorm is at least as plausible as the house warming stacks the deck in favor idea that this storm was simply a freak
Oceanography | March 2013 13